The exposome : promises and challenges of a new concept

The exposome was defined in 2005 as encompassing the totality of environmental exposures (in the broadest sense, including everything non-genetic) experienced since conception, as a counterpart to the genome. Characterization of a significant fraction of the human exposome is now possible thanks to the sensitivity of biochemical tools such as mass spectrometry and chromatography, applied to the biological sample banks of epidemiological cohorts. This quantification of the human exposome opens the way to descriptive studies of the exposome (illustrated in the seminar), of its variations with social categories (notion of environmental justice) and to the quantification of links between exposome and health. This concept, recent in its application, sheds new light on issues at the interface between epidemiology and data science, such as multiple comparisons, trade-offs between sensitivity, false positive rates and statistical model stability. The parallel with developments in research into the genetic causes of pathologies and the results of the first major projects on the exposome will enable us to discuss the challenges (including that of not succumbing to the "curse of size") and promises of this concept (including that of increasing the rate of knowledge generation on the links between the environment and human health).